I. What are the effects of a transmission oil leak on a car?
The transmission is a very precise assembly with a complex structure. Once it malfunctions, repairs are quite troublesome, and oil leaks are a common problem. So, what are the dangers of a transmission oil leak?
If the transmission oil leaks, the car will be difficult to start, there will be a jolt when shifting low gears, and the car will struggle to gain speed while driving, experiencing slippage. This is especially true for automatic transmissions, as automatic transmissions rely on a hydraulic system for shifting; a leak means they cannot shift gears. In severe cases, a low oil level can also cause abnormal noises from the transmission, requiring immediate repair.
II. What causes transmission oil leaks?
Transmission fluid is like the “blood” of the transmission. If it leaks, it’s like blood loss in a person—very dangerous. It’s crucial to find the cause of the leak and repair it promptly. Common causes of transmission oil leaks include:
- Aging or deformed oil seals, detached oil seal springs, or incorrectly oriented oil seals, causing the seals to lose their oil-blocking function.
Worn or dented journals, resulting in poor fit with the oil seal and causing leaks.
Damage to the gearbox housing mating surfaces, damaged gaskets, or loose cover screws can cause oil leaks at the gearbox mating surfaces.
Damaged gaskets, loose screws, or blocked gearbox vents can cause oil leaks at the bearing front mating surfaces.
Gear oil levels exceeding the specified standard can also cause gearbox oil leaks.
Excessive clearance at the shaft ends, loose bearing housings and bearings, damaged or failed gaskets, and damaged or missing gaskets.
Improper use of lubricating oil can cause excessive foaming in the lubricating oil within the gearbox, leading to a rise in the fluid level and ultimately, oil leaks.
III. How to Deal with a Transmission Oil Leak
If your transmission is leaking oil, you need to deal with it promptly. Sometimes it’s a non-continuous leak with little impact. However, if the leak is severe, you should stop your car immediately and take it to the nearest repair shop or 4S dealership. If you know how to repair a car, you can temporarily fix it before going for a proper repair. Specific steps are as follows:
- First, wipe the oil residue off the transmission with a cloth or paper towel. Inspect the leaking part to determine which side is leaking from, and then proceed with further diagnosis.
If the connecting bolts are loose, simply tighten the nuts.
If the gasket is damaged, replace it with a new one. Ensure the vent is clear and add oil to the transmission.
If the journal is leaking, repair the worn weld or replace the part.
Note: The above are temporary solutions. A transmission oil leak indicates an internal problem and should be inspected and repaired promptly to prevent further damage.